(I008)Ultra-rapid heating of Si wafer and GaN thin film and microwave heating mechanism

摘要

Semiconductor light emitting devices such as LED have excellent characteristics of power-saving, low voltage driving, and so they are used in various applications. LED elements are composed of different thin films such as GaN, transparent electrode on sapphire substrate. Microwave processing has many advantages such as rapid heating, selective heating and internal heating, and has begun to be applied to various heat treatments [1]. The heating is influenced by the permittivity of materials in microwave region. In this paper, we investigated the relationship between complex permittivity and microwave heating of LED elements. Next, we measured the complex permittivity of Si wafers and GaN thin films of different types in microwave region, and then the relationship between the electric conductivity (reciprocal of resistivity) and the microwave absorption was investigated. Furthermore, using a single mode cavity, we examined the influences of the resistivity of these samples, the substrate angle and electric (E) / magnetic (H) fields on microwave heating. The microwave heating mechanism of semiconductor materials will also be discussed.